Pressure-equalizing accessory for cables

ABSTRACT

A cable-pressure-equalizing accessory having a cup-shaped member fixed to the outer end of a tubular fitting. The latter is equipped with adjustable split ring means for holding the tubular fitting seated in an opening through a cable sheath in a manner excluding moisture and foreign matter while equalizing the internal cable pressure with the ambient pressure.

United States Patent Inventors John T. Thompson 244 Luring St., LosAngeles, 90024; George W. Gillemot, 2331 20th St., Santa Monica, Calif.90405 Appl. No. 879,137

Filed Nov. 24, 1969 Patented Feb. 16, 1971 PRESSURE-EQUALIZING ACCESSORYFOR CABLES 6 Claims, 7 Drawing Figs.

[1.8. CI 174/135; 174/12; 174/16 Int. Cl H011) 7/00, H02g 15/00 FieldofSearch 174/1, 8,

ll, l2, 13, 15C, 16,70,71, 135

[56] References Cited UNITED STATES PATENTS 2,011,561 8/l935 Chase174/12 2,859,270 ll/l958 Patchin 174/16 FORElGN PATENTS 1,060,529 1H1953 France 174/8 1,106,895 3/1968 Great Britain..,. l74/23 PrimaryExaminer-Laramie E. Askin Attorney-Sellers andBrace ABSTRACT: Acable-pressure-equalizing accessory having a cup-shaped member fixed tothe outer end of a tubular fitting. The latter is equipped withadjustable split ring means for holding the tubular fitting seated in anopening through a cable'sheath in a manner excluding moisture andforeign matter while equalizing the internal cable pressure with theambient pressure.

r P RL'ESSURE-EQUALIZING ACCESSORY I'DR'CABLES I .This invention relatesto-electrical cablesand more particularlyfto an improvedpressure-equalizing accessory readily assembled to a cable sheath toavoid vthe possibility. of a pressure differential between the interiorand exterior of the cable.

The accessory hasa flanged tubular fitting supporting a f s'hitpedshroud member with its open end-facingdownwardly and enclosing fineforaminous material crosswise of its interior effective to bar the entryof foreign matter. The installed accessory places the interior of thecable in direct communication with the atmosphere thereby avoiding-thepossibility of a pressure differential between the interior and exteriorof the cable'despite .changing atmospheric pressures and temperatures.'

Accordingly the primary object, of the present invention is toprovide animproved cable pressure-equalizingaccessory. f Another object of theinventionis .to provide simple,.inexpensive construction easilyinstalled on cables at intervals and operating to vent the interiorofthe cables to the atmosphere while'excluding foreign material andmoisture.

These and other more specific" objects will appear upon reading thefollowing specification and claims and upon con sidering in connectiontherewith the attached drawing to which they relate.

Referring now to the drawing in which a-preferred embodimerit of theinvention is illustrated: FIG. 1 is an exploded perspective view of onepreferred embodiment; FIG. 2 is a cross-sectional view of theFIGJ-embodiment shown installed on a cable;

FIG. 3 is a fragmentary cross-sectionalview taken along line Referringinitially and more particularlyto FIGS. 1 and 2 there is shown a typicalembodiment of the invention pressure equalizer, designated generally 10.Thisaccessory comprises a tubular fitting 11 having a threaded outer end12 encircled closely adjacent its rounded forward end 14'witha radialflange 13. A thick gasket ring 15 of'neoprene or the like has a snug fitover end 14 and seats against the forward face of flange 13. The rearface of flange 13 supports the inner surface of a plaque of thinsheetmetal 17 having a length adequate to form a split ring encirclinga'cable to whichaccessory l0'is to be attached with a substantialoverlap of its op posite ends. Strip 17, preferably formed of stainlesssteel or aluminum alloy, isprovided with an'opening offset from one endand provided with an upstanding flange 19 the intemaldiameter of whichis slightly less than that of fitting 11 at the base of threads 12. Itwill be understood that strip 17 is forced downwardly over fitting 1-1causingthe out-turned flange 19 thereof to be expanded slightly as it isforcibly pressed over thejenlarged base end of threads 12. The exteriorof the fitting at this enlarged portion may be axially scored so thatflange 19 mechanically interlocks therewith during assembly.

Applied to the inner side of the split ring member 17 is a plaque 20 ofthick tacky material such as buna well known for its durability, sealingand adhesive characteristics. Prior to installation, its outer surfaceispreferably protected withagsheet 4 of waxy paper or the (like.21;which.is readily peeled away just prior to assembly of the'accessoryto a cable.

The means shown. in FIGS. -I,3 for. holding the split-ring... snuglyclamped about a .cable of conductors 23,-. comprises a pair of.clampingbands 24,25 of any wellknown-cornmercial type having their endsoverlapping and adjustable relative tb. one another by rotation ofascrew 26,27 having its threads engaged with short slotsformed crosswiseof the clamping-band. It will be understoodthatany suitable type ofclamping band:

may be employed.

Protecting the outer end of fitting 11 againstentry light weightnoncorrosivemetal. In the lattercase, it maybe protected withan anodizedor other suitable coating.

The installation of equalizer 10 will be readily apparen l from theforegoing description. First a small opening 3'7is formed inthe sheath36.of cable 23. Desirably,.this openingli'sformed on the underside .ofthe cablesheath and is sized to receive theforward end 14 of fitting.11. It is important that this end not protrude beyond the inner end ofopening 37 as. thiscould interfere with or damage the electricalconductors enclosed by sheath-3.6.

The tackinessof plaque 20 aids very materially in holding the deviceinplace while the clamping .bands 24.25 are being inserted over theopposite lateral edges of ringlet 17. The clamp; ing screws 26,27 arethen progressively tightened pressing the layer of tacky materialagainst thesheath andexpanding thisv materiallaterally until its outeredges lie substantially even with the adjacent edges of member 17. Ifthecup-shaped member 30 has notbeen assembled to threads 12, this isdone, thereby completing the assembly operation. The central bore 40through tubular fitting 11 is in freecommunication with the interior ofthe cablesheath andwith-the atmosphere through the downwardly openingshroudmember,30, Any change in pressure conditions between theinteriorand exterior of the cable are immediately equalized through thispassage and member 30.

Referring now to the modification-shown in FIG. 4, it is pointed outthat this embodiment differs from the firstdescribed constructionessentially in the use of athreaded nipple .42 to hold shroud member 30'to the internally threaded outer end of fitting -11. Otherwise, the twoembodiments are constructed and installed in the same mannerand-theirsimilar elements are designated by the same reference characters butdistinguished by the addition of a prime.

Referring to FIGS. 5 and 6, there is shown a further simple embodimentof the invention, the same or corresponding ele.-- merits beingdesignated by the same reference characters as the FIGS. 1=-3 butdistinguished byathe addition of a double prime. A principal differencebetween the FIG. 3.and 4 and the FIG. 5 and 6'embodiment is that thesplit ring member 17' is provided with an attached adjustable take upmeans 26" so that its overlapping ends can be contracted to clamp device10" securely to the cable. Although shroud cup 30 is shown of I moistureandforeign matter is a deepcup-shaped member .30 having a threadedopening- 31 in its bottom .mating with threads 12 of fitting llpTheshouldered interior side wall of member 30 supports fine wire mesh orother. foraminotrs, material 33 .heldinplace by keeper ring 34 andindentations. 35. Cup member 30may be molded of plastic or formedfrorn.

Still another embodiment of the pressure-equalizing accessory is shownin FlG. 7 and suitable for installation on cables 23" having a metalsheath. The tubular fitting interconnecting the cableand cup. 30"comprises an elbow 11" threaded at its opposite ends and preferablysealed to the cable sheath by solder 45 or a suitable adhesive. Thisembodiment may also be installed on cables having a plastic sheath usingan adhesive to form a seal with the sheath. The elbow fitting 11" isinstalled inone side of a cable in the manner illustrated in FIG. 7 withthe open end of shroud 30" facing downwardly. This mode of installationhas advantages under certain operating conditions.

While the particular pressure-equalizing accessory for cables hereinshown and disclosed in detail is fully capable of attaining the objectsand providing the advantages hereinbefore stated, it is to be understoodthat it is merely illustrative of the presently preferred embodiments ofthe invention.

We claim:

l. A cable-pressure'equalizing accessory for safeguarding against apressure differential across a cable sheath, said accessory comprising atubular member having a wide radial flange spaced close to one endthereof, a seating gasket supported on said flange and adapted to seatagainst the exterior rim edge of a hole through .a cable sheath,split-ring-forming means embracing said tubular member and bearingagainst the opposite side of said flange from said gasket and adapted toencircle a cable sheath and including means for clamping saidring-forming means snugly against the exterior of a cable sheath, and acup-shaped shroud member having an opening through the bottom thereofassembled to and in communication with the end of said tubular memberremote from said gasket.

2. A pressure-equalizing accessory as defined in claim 1 characterizedin that said split-ring-forming means is fixed to said tubular memberand has said clamping means mounted thereon.

3. A pressure-equalizing accessory as defined in claim 1 characterizedin that said cup-shaped shroud member is formed of anodized aluminum andincludes means for holding the same detachably assembled to said tubularmember.

4. A pressure-equalizing accessory as defined in claim 1 characterizedin that said split-ring-forming means comprises a thin flexible metalstrip having a thick wide plaque of tacky material on the face thereofadjacent said gasket strongly adherent to said metal strip and to acable sheath when pressed thereagainst, and said clamping meansembracing the opposite lateral edges of said metal strip being disposedto either side of said tubular member and adjustable to clamp said stripand said tacky plaque firmly against the exterior of a cable sheath withone end of said tubular member projecting into an opening through thewall of the sheath.

5. A pressure-equalizing accessory as defined in claim 4 characterizedin that said plaque of tacky material has an opening therein sized toseat about the rim of said gasket.

6. A pressure-equalizing accessory as defined in claim 4 characterizedin that said cup-shaped shroud member includes fine foraminous materialextending crosswise of its interior effective to pass air but barringthe passage of foreign matter.

1. A cable-pressure-equalizing accessory for safeguarding against apressure differential across a cable sheath, said accessory comprising atubular member having a wide radial flange spaced close to one endthereof, a seating gasket supported on said flange and adapted to seatagainst the exterior rim edge of a hole through a cable sheath,split-ring-forming means embracing said tubular member and bearingagainst the opposite side of said flange from said gasket and adapted toencircle a cable sheath and including means for clamping saidring-forming means snugly against the exterior of a cable sheath, and acup-shaped shroud member having an opening through the bottom thereofassembled to and in communication with the end of said tubular memberremote from said gasket.
 2. A pressure-equalizing accessory as definedin claim 1 characterized in that said split-ring-forming means is fixedto said tubular member and has said clamping means mounted thereon.
 3. Apressure-equalizing accessory as defined in claim 1 characterized inthat said cup-shaped shroud member is formed of anodized aluminum andincludes means for holding the same detachably assembled to said tubularmember.
 4. A pressure-equalizing accessory as defined in claim 1characterized in that said split-ring-forming means comprises a thinflexible metal strip having a thick wide plaque of tacky material on theface thereof adjacent said gasket strongly adherent to said metal stripand to a cable sheath when pressed tHereagainst, and said clamping meansembracing the opposite lateral edges of said metal strip being disposedto either side of said tubular member and adjustable to clamp said stripand said tacky plaque firmly against the exterior of a cable sheath withone end of said tubular member projecting into an opening through thewall of the sheath.
 5. A pressure-equalizing accessory as defined inclaim 4 characterized in that said plaque of tacky material has anopening therein sized to seat about the rim of said gasket.
 6. Apressure-equalizing accessory as defined in claim 4 characterized inthat said cup-shaped shroud member includes fine foraminous materialextending crosswise of its interior effective to pass air but barringthe passage of foreign matter.